Crane system for hoisting of wind turbine components

Abstract

A crane system for moving a burden, such as a wind turbine component, between the nacelle or rotor of a wind turbine and a location at a lower end of the wind turbine at a distance from the wind turbine, wherein the crane system includes a crane, said crane being adapted to be mounted near or in the nacelle of the wind turbine, wherein said crane includes a boom and wherein the crane has at least one rotational axis, about which sections of the crane can rotate. The disclosure further relates to a method for moving a burden, such as a wind turbine component, between the nacelle or rotor of a wind turbine and a location at a lower end of the wind turbine at a distance from the wind turbine.

What is claimed is: 
     
       1. A crane system for moving a burden between a location near a top of a wind turbine and a location at a lower end of the wind turbine at a distance from the wind turbine, wherein the crane system comprises:
 a crane configured to be mounted near or in a nacelle of the wind turbine and comprising a boom, wherein the crane has at least one rotational axis about which sections of the crane can rotate; 
 a lower cable support system configured to be arranged at the lower end of the wind turbine at the distance from the wind turbine; 
 an upper cable support system configured to be mounted on the wind turbine at a height higher than the lower cable support system; 
 a first cable configured to be extended between the upper cable support system and the lower cable support system; and 
 a load carrying device comprising:
 a first structural section, and 
 a first linkage, wherein the first structural section comprises at least a first roller configured to roll on the first cable, and wherein the first linkage is configured to connect the load carrying device to the burden. 
 
 
     
     
       2. The crane system of  claim 1 , wherein the upper cable support system is located near or in the nacelle of the wind turbine. 
     
     
       3. The crane system of  claim 1 , wherein, when the first roller is engaged with the first cable, the first linkage is located below the first cable. 
     
     
       4. The crane system of  claim 1 , wherein the load carrying device has:
 a roller plane that is parallel to an axis of rotation of the first roller, intersects the first roller in at least one point, and is being perpendicular to a line extending between the first linkage and the axis of rotation of the first roller, wherein the line is perpendicular to the axis of rotation of the first roller, and wherein a center of mass of the load carrying device is located on a side of the roller plane that is towards the first linkage. 
 
     
     
       5. The crane system of  claim 1 , wherein the first linkage comprises an extendable section configured to vary in length. 
     
     
       6. The crane system of  claim 1 , wherein the load carrying device further comprises:
 a second structural section connecting the first structural section and the first linkage, wherein the second structural section comprises an extendable portion configured to vary in length. 
 
     
     
       7. The crane system of  claim 1 , further comprising:
 a tensioning device configured to adjust tension in the first cable. 
 
     
     
       8. The crane system of  claim 7 , wherein the lower cable support system comprises the tensioning device. 
     
     
       9. The crane system of  claim 1 , wherein:
 the first cable is connected to the crane at a first end of the first cable, and 
 the upper cable support system is between the first end of the first cable and the lower cable support system. 
 
     
     
       10. The crane system of  claim 1 , further comprising:
 a second cable, wherein the first cable and the second cable are independently connected to the upper cable support system and the lower cable support system, and wherein the load carrying device comprises: 
 a second roller, wherein the first roller and the second roller are configured to roll on the first cable and the second cable respectively. 
 
     
     
       11. A method for moving a burden between a nacelle or a rotor of a wind turbine and a location at a lower end of the wind turbine at a distance from the wind turbine, the method comprising:
 connecting a first cable between a lower cable support system that is configured to be arranged at the lower end of the wind turbine at the distance from the wind turbine and between an upper cable support system that is configured to be mounted on the wind turbine at a height higher than the lower cable support system; 
 connecting the burden to a load carrying device comprising a first structural section and a first linkage, wherein the burden is detachably attached to the first linkage and wherein the first structural section comprises a first roller; 
 lifting the burden using a crane mounted near or in the nacelle of the wind turbine; 
 placing the first structural section of the load carrying device on the first cable, wherein the first roller connects to the first cable in a rollable manner based on the placing; and 
 hoisting the burden up or down using the crane while the load carrying device is guided by the first cable. 
 
     
     
       12. The method of  claim 11 , further comprising:
 yawing the crane about a substantially vertical axis and hoisting the burden between a position attached to the wind turbine inside the nacelle and a free position outside of the nacelle hanging from the first linkage. 
 
     
     
       13. The method of  claim 11 , further comprising:
 connecting a second cable between the lower cable support system and the upper cable support system; and 
 placing the first structural section of the load carrying device on the first cable and the second cable, respectively, in the rollable manner. 
 
     
     
       14. The method of  claim 11 , further comprising:
 extending an extendable portion of the first linkage, wherein the first linkage switches between a retracted configuration and an extended configuration based on the extending. 
 
     
     
       15. The method of  claim 11 , further comprising:
 extending an extendable portion of a second structural section of the load carrying device, wherein the second structural section switches between a retracted configuration and an extended configuration based on the extending. 
 
     
     
       16. The crane system of  claim 1 , wherein a length of the first cable between the upper cable support system and the lower cable support system is parallel to a length of a second cable between the upper cable support system and the lower cable support system. 
     
     
       17. The crane system of  claim 1 , wherein the load carrying device comprises:
 an attachment point that is one of a lifting eyelet, a shackle, or a bolt. 
 
     
     
       18. The crane system of  claim 1 , further comprising:
 a secondary tensioning device located between the upper cable support system and the lower cable support system at a location near the upper cable support system, wherein the secondary tensioning device changes an angle and a position of the first cable by pulling the first cable towards a tower of the wind turbine when retracted. 
 
     
     
       19. The crane system of  claim 1 , wherein the burden is a wind turbine component, a transformer, or both. 
     
     
       20. The crane system of  claim 5 , wherein the first linkage is a cylinder, a lead screw, or a chain hoist.